mounting my solar panels

Darklock wrote:
I have ordered some solar panels to put on my TT. I bought the 200 watt kit from Renogy. I doubt that I will be able to determine where the structural members are, so there is the very real possibility that if I just use screws they will only be into the plywood decking. In any other applications, I would trust this, but not for going down the highway at 60mph. Therefore, I am thinking of using expanding well nuts. Good plan? Or does the collective here feel that the screws should be enough?
Also, what is best sealant to insure no leaks? No clue what the roof surface is. TT is a Gulfstream Conquest.
Bil

I just went thorough this. I did not buy Renogy Panels but I did buy Renogy mounting brackets. The brackets come with mounting screws four per bracket. The first screw I put in did not bite. The screw is a number 10 or less. Fine threads. As soon as that happened I went down to the hardware store and got some round head number 12 x 1 stainless screws that have a course thread for biting into wood. These worked great no pilot hole just screw them in with impact driver being careful not to over torque. As soon as the driver ratcheted and screw head was flush that was it.

Prior to screwing down the brackets I cleaned with a little acetone I put a small strip of Eternabond between the roof membrane and the Renogy bracket. Eternabond will self seal around the screws as they pass through.

I used Dicor self leveling sealant to seal the screw heads and around the brackets. I was very generous with the Dicor. Which may have caused a little ripple affect with the roof membrane as it began to dry which I discovered the next day. I contacted Dicor about this by email which they did not respond too but I did find written information from Dicor that said the following.

"Lap sealants formulated for RV roofs, on the other hand, are made to bite into the EPDM or TPO roof material (Dicor lap sealant also works with metal and fiberglass) and hold fast. In the case of a common EPDM roof, lap sealants like Dicor's self-leveling and non-sag, non self-leveling sealants contain an oil-based solvent that reacts with the oil-based elements in the roofing material. At first, this reaction will actually cause the roofing material to swell a bit — you might even get a slight rippling effect. But don't worry! This is only temporary while the reacting oils evaporate, which brings the roof back to its normal state and, most importantly, essentially fusing the sealant and roofing material together".

It's been 3 weeks or so since I installed my panels and the rippling affect has improved but not perfect. Waiting for some nice hot days.

Yes, drilling 16 screws per panel x five panels is 80 holes but do a good job and forget about it.